Orthodontic appliance force equalizer

ABSTRACT

An orthodontic appliance force equalizer for equalizing the tension on an orthodontic appliance such as a conventional face bow in which a coil spring reel is carried within a housing mounted on a headband and within which the coil spring acts to maintain an adjustable but constant tension. A cord such as a nylon cord is wrapped around the coil spring reel from opposite directions and is in turn attached to each end of the orthodontic face bow with the spring being partially coiled to exert a predetermined tension or force on the face bow. The reel is rotatably mounted to the case for paying out and taking up the cord as dictated by movement of the patient&#39;&#39;s head. The entire assembly is carried in the manner of a headband or neckband on the back of the patient&#39;&#39;s head.

United States Patent [191 Andrews Nov. 11, 1975 ORTHODONTIC APPLIANCE FORCE EQUALIZER [75] Inventor: Lawrence F. Andrews, San Diego,

Calif.

[73] Assignee: Lawrence F. Andrews, San Diego,

Calif.

[22] Filed: Aug. 24, 1973 [21] App]. No.: 391,129

[52] US. Cl 32/14 D [51] Int. Cl. A61C-7/00 [58] Field of Search 32/14 D, 14 R; 267/156; 242/1071, 107.11

[56] References Cited UNITED STATES PATENTS 422,381 3/1890 Cole 242/lO7.11 3,197,155 7/1965 Yutchow 242/107.l 3,686,757 8/1972 McVickers et a1. 32/14 D 3,772,789 11/1973 De Weoskin 32/14 D Primary Examiner-Robert Peshock Assistant E.\'antinerJ. Q. Lever Attorney, Agent, or FirmRichard K. Macneill [5 7 ABSTRACT An orthodontic appliance force equalizer for equalizing the tension on an orthodontic appliance such as a conventional face bow in which a coil spring reel is carried within a housing mounted on a headband and within which the coil spring acts to maintain an adjustable but constant tension. A cord such as a nylon cord is wrapped around the coil spring reel from opposite directions and is in turn attached to each end of the orthodontic face bow with the spring being partially coiled to exert a predetermined tension or force on the face bow. The reel is rotatably mounted to the case for paying out and taking up the cord as dictated by movement of the patients head. The entire assembly is carried-in the manner of a headband or neckband on the back -of the patients head.

1 "Claim, 12 Drawing Figures U.S. Patent Nov.11, 1975 Sheet1of2 3,918,159

US. Patent Nov. 11, 1975 Sheet20f2 3,918,159

ORTHODONTIC APPLIANCE FORCE EQUALIZER PRIOR ART The following patents were turned up in a search of the prior art: U.S. Pat. Nos. 3,526,035, 3,119,182, 3,686,757, 3,512,257, and 3,648,372.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an orthodontic appliance force equalizer and more particularly to can orthodontic appliance force equalizer having a single mechanism carried centrally in the back portion of the patients head.

According to the invention, an orthodontic appliance force equalizer is provided in which a spring and reel assembly is mounted within a housing. A pair of plyable and/or flexible lines are carried by the reel from opposite sides thereof for attachment to each end of an orthodontic face bow. These can be nylon cord for example. As the patient turns, or twists his head, the reel can pay out line which will not appreciably vary in preset tension. Hence, the patient will have much more freedom of movement as for example while sleeping. A further advantage of utilizing a single equalizing tension unit placed at the back of the patients head (rather than having one on each side) is to allow the patient to sleep on either side without being encumbered by the force equalizing unit. In a more sophisticated embodiment the reel is split into two reels with on reel fixedly attached to a spindle and with the spindle rotatably carried by the case. The other reel is not coupled to the spindle, but rotatably coupled to the case. In this embodiment, the inside end of the spring is still attached to the spindle with the outside end of the spring being attached to the reel that is not coupled to the spindle. Hence, the reels can operate independently of each other which allows for equalization of tension on the orthodontist face bow.

An object of the present invention is the provision of an orthodontic appliance force equalizer for application to orthodontic face bows.

Another object of the invention is the provision of an orthodontic force equalizer utilizing a single tension mechanism for mounting at the back of the patients head.

A further object of the invention is the provision of a orthodontic appliance force equalizer which is inexpensive to manufacture and assemble and extremely convenient in use.

Other objects and many of the attendant advantages will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the FIGS. whereof and wherein:

FIG. 1 is a prospective view of one type of harness utilized in the present invention;

FIG. 2 is a prospective view of the orthodontic ap pliance force equalizer in the headband of FIG. 1;

FIG. 3 is a prospective view of another type of headband utilized with the present invention in Situ;

FIG. 4 is a back view of the embodiment of FIG. 3;

FIG. 5 is an exploded view in prospective of one embodiment of the present invention;

FIG. 6 is a transparent case top view of the reel assembly of FIGQS;

FIG. 7 is a top view of the spindle attached reel assembly of another embodiment of the present invention;

FIG. 8 is a top view of a complete reel assembly incorporating the single reel of FIG. 7;

FIGS. 9 and 10 illustrate a spring and reel assembly completing the embodiment of FIG. 8;

FIG. 11 illustrates the embodiment of FIG. 8 mounted in a housing; and

FIG. 12 illustrates the cover of the housing of FIG. 1 l in place on the housing but not secured.

DETAILED DESCRIPTION OF THE DRAWING Referring to FIG. 1, a patient 11 is shown wearing a headband 12 with a line 13 coupled to hook 14 of face how 16.

Referring to FIG. 2, face bow 16 is shown coupled to line 13 at hook l4 and coupled to line 17 at hook 18. Lines 13 and 17 pass within tunnel loops 19 and 21 respectively of headband 12. Headband 12 carries force equalizer assembly 22 which has lines 13 and 17 emerg ing therefrom.

Referring to FIG. 3, a user 11 is shown with a different type of headband 12A which carries force equalizer mechanism 22. Face bow 16 is attached to line 13 from orthodontic appliance equalizer mechanism 22 at hook 14. Line 13 passes through tunnel loop 19A.

Referring to FIG. 4 user 11 is again shown carrying head strap 12A with force equalizer mechanism 22 attached thereto and having lines I? and 17 emerging therefrom.

Referring to FIG. 5 a force equalizer assembly is shown generally at 22 having a housing 23 which rotatably carries a reel 24 with lines 13 and 17 emerging therefrom. A coil spring 26 is received on a spindle 27. Coil spring 26 has an inner end 28 which is attachable within slot 29 of spindle 27. Spindle 27 is fixedly attached to cover 31 which in turn mates with housing 23. Another end 32 of coil spring 26 is attached at internal lip 33 of reel 24.

Referring to FIG. 6 reel 24 is shown carrying line 13 on a bottom portion and line 17 at a top portion. The reel is shown mounted rotatably within housing 23.

Referring back to FIGS. 5 and 6, it is important that reel 24 rotate smoothly within housing 23. To achieve this, the inner diameter 24 of reel 24 rotates in close proximity to circular boss 31 of cover 31 and, at the opposite end, spindle bore 35 encircles spindle 27 which is firmly engaged in spindle stabilizer hole 34 of housing 23.

Referring to FIG. 7, one-half of a split reel 24A is shown attached to spindle 27A having a slot 29A therein and in proximity with a T cross-sectioned inner diameter bushing 25.

Referring to FIG. 8, one-half of reel 24A is shown separated from another half of reel 24B separated by an inner diameter, low friction, washer 25. Reel 24B carries line 13 and reel 24A carries line 17.

Referring to FIG. 9, spring 26A is shown having an outside end 32A.

Referring to FIG. 10, reel half 24B is shown having an internal lip 33A for carrying end 32A of spring 26A (FIG. 9) and a spindle bore 35A for cooperation with spindle 27A (FIG. 7).

Referring to FIG. 11, housing 23A is shown carrying reel24B with line 13A emerging therefrom and line 3 17A emerging from the spindle attached reel 24A (not visible). Spindle 27A is visible where it passes through spindle bore 35A in reel 24B and its slot 29A contains inner end 28A of spring 26A (not visible).

Referring to FIG. 12, cover 31 is shown having a spindle stabilizing aperture 34A for receiving small diameter end 30 of spindle 27A (FIG. 7).

OPERATION Referring back to FIGS. 1 and 2, it can be seen that headband 12 has force equalizer assembly 22 mounted thereto which has lines 13 and 17 emerging therefrom to attach to face bow 16 at hooks 14 and 18 respectively. The placement of the equalizing unit 22in the central back portion of the head has been found to result in maximum comfort to the wearer since when sleeping he can sleep on either side or on his back.

Referring to FIGS. 3 and 4, the same philosophy is utilized with the exception of raising the positioning of equalizing unit 22 closer to the top of the head.

Referring to FIG. 5, the equalizing mechanism is shown generally at 22. Spindle 27 having a slot 29, which receives inner end 28 of spring 26 is fixedly attached to cover 31 and thence to housing 23. Reel 24 receives spring 26 in its center and attaches at inner lip 33 to the outside end 32 of spring 26. Reel 24 is rotatably carried by housing 23 and cover 31. When lines 13 and 17 on reel 24 are pulled, reel 24 will rotate in a clockwise direction, but spring 26 supplies a tensioned resistance to such motion. It is pointed outthat lines 13 and 17 can be nylon cord, steel bands or any flexible or plyable material. When the appliance is tied to a face bow the coil spring 26 is partially wound resulting in spring tension on lines 13 and 17. As the patient moves his head in and out from his neck line and lines 13 and 17 are paid out or retracted the tension on the face bow will remain relatively constant due to the inherent characteristics of the coil spring.

Referring now to FIGS. 7, 8, 9, 10, 11 and 12, a second embodiment will be described. Here upper reel half 24A and lower reel half 24B carrying lines 17 and 13, respectively, are separated by a low friction washer 25 which maintains concentricity of rotation. These reel halfs then can rotate in opposite directions or in any one direction independently of each other. Here,

spindle 27A is fixedly attached and carries reel half 24A and is rotatably mounted to the housing 23A and cover 31A. The inner end 28A of spring 26A is attached to slot 29A of spindle 27A and the outer end 32A of spring 26A is carried by reel half 24]! at inner lip 32A. Hence when line 17 tends to increase its tension the line is paid out by reel half 24A and winds up spring 26A from the inside thereof. When tension is applied to line 13 reel half 24B pays out and winds up spring 268 at the outside end 32A. It can be seen that. the spring can be wound from each end simultaneously or unwound at one end and wound at the other, etc.

It should be understood,-of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all= changes and modifications of the example of the inven-. tion herein chosen for the purposes of the disclosure which do not constitute from the departures from the.

a spindlecarried by said housing concentric with said y reel assembly;

a coil spring disposed within said reel assembly, said coil spring having an inner end coupled to said spindle and an outer end attached to said reel assembly; and

said reel assembly consists of first and second reels with said first and second lines coiled thereon, respectively, said first and second lines being coiled in opposite directions;

said spindle being fixedly attached to one of saidfirst and second reels and rotatably coupled to said housing; and

said outside end of said spring being attached to another of said first and second reels. I 

1. An orthodontic appliance force equilizer for equalizing the tension on an orthodontic appliance such as a conventional face bow comprising: a housing; a reel assembly rotatably mounted within said housing; first and second lines coiled on said reel assembly, said first and second lines adapted for coupling to an orthodontic appliance; a spindle carried by said housing concentric with said reel assembly; a coil spring disposed within said reel assembly, said coil spring having an inner end coupled to said spindle and an outer end attached to said reel assembly; and said reel assembly consists of first and second reels with said first and second lines coiled thereon, respectively, said first and second lines being coiled in opposite directions; said spindle being fixedly attached to one of said first and second reels and rotatably coupled to said housing; and said outside end of said spring being attached to another of said fiRst and second reels. 